Ricerc@Sapienza

In this case report, we studied Theory of Mind (ToM) and figurative language
comprehension in a 7.2-year-old child, conventionally named RJ, with isolated and
complete agenesis of the corpus callosum (ACC), a rare malformation due to the
absence of the corpus callosum, the major tract connecting the two brain hemispheres.
To study ToM, which is the capability to infer the other’s mental states, we used
the classical false belief tasks, and to study figurative language, i.e., those linguistic
usages involving non-literal meanings, we used tasks assessing metaphor and idiom
comprehension. RJ’s intellectual level and his phonological, lexical, and grammatical
abilities were all adequate. In both the ToM false belief tasks and novel sensory metaphor
comprehension, RJ showed a delay of 3 years and a significant gap compared to a
typically developing control group, while in idioms, his performance was at the border of
average. These outcomes suggest that RJ has a specific pragmatic difficulty in all tasks
where he must interpret the other’s communicative intention, as in ToM tasks and novel
sensory metaphor comprehension. The outcomes also open up interesting insights into
the relationships between ToM and figurative language in children with isolated and
complete ACC.